The present invention relates to ink jet printers, and more particularly, it relates to ink jet printers in which sub tanks are mounted at the side of recording heads, and main tanks are provided at the side of the printer body, and ink filled in the main tanks are supplied to the sub tanks and recording is carried out by the recording heads of ink jet type.
The ink jet printers are disclosed in Japanese Patent Laid-open Publication No. H 10-86395 and other publications in which sub tanks for ink are mounted at the side of recording heads, and main tanks for ink are mounted at the printer body side, and the ink is supplied from the main tanks to the sub tanks, and the ink is supplied from the sub tanks to the recording heads, and the ink is discharged from the recording heads to the paper to carry out a drafting. Also, in Japanese Patent Laid-open Publication No. H 05-294528, the ink jet printer is disclosed in which the paper is guided onto a large diameter platen roller, and a drafting is carried out by the ink jet head on this platen roller.
As the ink for recording on the paper, the solvent ink has heretofore been known. This solvent ink has an advantageous point that the recorded surface keeps its ink stuck to the surface since the ink is fully dissolved therein. For this reason, there is no necessity of coating a protective film such as a lamination on the recording surface on which the recording is applied with the solvent ink.
However, the solvent ink has an alcoholic ingredient that has high volatility which is easily dried up as compared with aqueous ink, but on the other hand, it instantly becomes solid. Also, there is a quality that if it remains as it is, the pigment ingredient separates. Accordingly, in order to use such solvent ink and other easily volatile inks for use in the ink jet printers, a sealing quality is required in whole of ink supply paths, and basically, contact of the ink with atmosphere should be prevented as much as possible, and evaporation of the ink must be prevented. For this purpose, there is a need for keeping the ink in the recording heads, tubes, sub tanks for a long period of time. Furthermore, unless the ink is periodically stirred and mixed, there is an apprehension that the ink ingredient tends to separate.
An object of the present invention is to solve the foregoing points.